When receiving the anonymous letter suggesting to check the digitalis levels in order to reveal murder, the secretary says she 'tried to handle it as little as possible as soon as it came in'. Nevertheless, the Police Commissioner does nothing to prevent tampering and grabs the note with both hands, smearing it all over with his fingerprints and then hands it to Jessica (who is slightly more cautious and handles it with minimum finger contact).
When at a Philadelphia airport, mountains are seen in the background. The closest mountains to be seen near any area airport are a 2 hour drive.
At the wake, the camera shoots down into the coffin. The "corpse" can be clearly seen to be breathing with large chest movements.
Towards the end of the episode, after being thrown into the hutch, the uncredited actress who plays Lydia Thurlow can be seen holding the fake glass shard in place as she falls to the ground. She also puts her hands out to cushion the blow as she falls down. A person who had just been impaled would not be of the mind presence to protect themselves from further injury.